The endocannabinoid system is an active and complex cell signaling network. It involves a combination of endocannabinoids, enzymes, and cannabinoid receptors that help regulate several functions in the human body.

The discovery of the ECS is relatively new. In the early 1990s, a chemist isolated the first endocannabinoid in the human brain. Since that time, researchers have been learning more about this system and the role it plays in bodily functions.

Endocannabinoids are similar to the cannabinoids present in the cannabis sativa (C. sativa) plant. However, the human body naturally produces endocannabinoids. The term “endo” refers to “within,” as in within the body.

In this article, we will define the endocannabinoid system, and examine its function and potential therapeutic uses.

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The endocannabinoid system (ECS) is a biological system in the body that helps regulate and balance key bodily functions.

Research suggests that the ECS may be a potential therapeutic target in numerous physiological conditions such as:

  • energy balance
  • appetite stimulation
  • blood pressure
  • pain
  • embryonic development
  • nausea and vomiting control
  • memory and learning
  • immune response

In addition, it may be a target for pathological conditions such as:

  • Parkinson’s disease
  • Huntington’s disease
  • Alzheimer’s disease
  • multiple sclerosis

Although more research is still necessary to gain a better understanding of the system, researchers know that it involves three main components:


Endogenous cannabinoids, or endocannabinoids, are naturally occurring, lipid-based neurotransmitters. Neurotransmitters are chemical messengers in the body that send signals between nerve cells.

Endocannabinoids help with various bodily functions. The body produces them as necessary, which makes it difficult to know what typical levels are.

Two of the main endocannabinoids identified include:

  • Anandamide (AEA or arachidonoyl ethanolamide)
  • 2-archidonoyl glyerol (2-AG)

Experts believe there are additional endocannabinoids in the body, but their roles and functions are not definitively known yet.

Endocannabinoid receptors

Cannabinoid receptors are on the surface of cells throughout the body. Endocannabinoids attach or bind to the receptors, which sends a message to the ECS to kick-start a response.

The two primary cannabinoid receptors are present throughout the body:

Experts think a third cannabinoid receptor may also exist, but research is not conclusive.

Endocannabinoids may attach to either type of receptor, causing different results depending on the location of the receptor in the body.

For example, endocannabinoids may target CB1 receptors in a spinal nerve to relieve pain or bind to a CB2 receptor in an immune cell, which signals that the body is experiencing inflammation.


Enzymes are responsible for breaking down the endocannabinoids after they carry out the needed response. The two main enzymes that break down endocannabinoids are:

  • fatty acid amide hydrolase, which breaks down AEA
  • monoacylglycerol acid lipase, which breaks down 2-AG

The human body naturally produces endocannabinoids. They are present in various organs and tissues, such as the muscle, brain, and circulating cells. Endocannabinoids become active when they bind with a cannabinoid receptor. The receptors are also located throughout the body.

Research continues on the exact physiological mechanism that promotes or triggers the binding of the receptors to the endocannabinoids. But experts theorize that when a system in the body is out of balance, the receptors bind to the cannabinoids to help correct the problem.

The endocannabinoid system is precise. For example, if body temperature is out of the normal range, the ECS regulates it without altering other processes. Once the ECS brings the body back into balance, the enzymes break down the cannabinoids to prevent overcorrecting the problem.

The function of cannabinoids within the ECS is vast. In fact, researchers still do not fully understand the exact role of cannabinoids, although the ECS clearly plays a large part in how well the body functions.

Research suggests that the ECS plays a key role in contributing towards homeostasis. Homeostasis refers to the maintenance of stability, or optimal conditions, within the body to promote proper functioning.

For example, the body maintains homeostasis for temperature, blood sugar, and appetite. Experts believe that if the body falls out of the normal range, the ECS helps the body to return to the optimal range and maintain homeostasis.

Research suggests the ECS may help regulate the function of the following:

  • appetite and digestion
  • sleep
  • Pain sensation
  • inflammation and other immune responses
  • mood
  • metabolism
  • learning and memory
  • reproduction system function

Research indicates that the ECS may contain multiple promising therapeutic targets. While the body can produce endocannabinoids, there are also many cannabinoids present in the C.sativa plant which are of medical interest.

Two of the most well-known cannabinoids include tetrahydrocannabinol (THC) and cannabidiol (CBD). They can also bind to cannabinoid receptors and produce similar effects to endocannabinoids. THC is the cannabinoid that causes the “high” that people may associate with cannabis, whereas CBD does not produce this sensation.

Studies are ongoing to determine the therapeutic benefits of cannabinoids. For example, a 2016 study investigated the effect of CBD on joint inflammation in rats. The study suggests that applying a topical gel containing CBD decreased pain and joint swelling in rats without side effects.

Additional research indicates that cannabinoids may be helpful in treating a variety of conditions such as:

  • pain in adults
  • abnormal muscle tightness associated with multiple sclerosis
  • nausea and vomiting associated with chemotherapy
  • sleep disturbances

Research continues on how inhibiting or stimulating the endocannabinoid system could have medical and health benefits.

Not everything is known about the ECS, but research suggests that it plays a vital part in maintaining balance and proper function in the body.

The ECS consists of endocannabinoids, receptors, and enzymes, which work together to help maintain stability in processes such as temperature, sleep, and mood.

The ECS may contain many therapeutic targets, which researchers may be able to use to help treat various health conditions.